gsdx mipmap:ogl: plug trilinear/mipmap2 option

mipmap option 3. Actually maybe a separate tri-linear option will be better

m_mipmap == 2 => use manual PS2 trilinear/mipmap
Otherwise
m_filter == 3 => always use full automatic trilinear interpolation
m_filter == 4 => use automatic trilinear interpolation when PS2 uses mipmap
m_filter == 5 => like 4 but force bilinear interpolation inside layer

plugins/GSdx/GSDeviceOGL.cpp

@@ -75,6 +75,7 @@ GSDeviceOGL::GSDeviceOGL()
 	GLState::Clear();
 
 	m_mipmap = theApp.GetConfigI("mipmap");
+	m_filter = theApp.GetConfigI("filter");
 
 	// Reset the debug file
 	#ifdef ENABLE_OGL_DEBUG
@@ -229,7 +230,7 @@ GSTexture* GSDeviceOGL::CreateSurface(int type, int w, int h, bool msaa, int fmt
 
 	// A wrapper to call GSTextureOGL, with the different kind of parameter
 	GSTextureOGL* t = NULL;
-	t = new GSTextureOGL(type, w, h, fmt, m_fbo_read, m_mipmap > 1);
+	t = new GSTextureOGL(type, w, h, fmt, m_fbo_read, m_mipmap > 1 || m_filter > 2);
 	if (t == NULL) {
 		throw GSDXErrorOOM();
 	}

plugins/GSdx/GSDeviceOGL.h

@@ -405,6 +405,7 @@ public:
 	uint32 m_msaa;				// Level of Msaa
 	int m_force_texture_clear;
 	int m_mipmap;
+	int m_filter;
 
 	static bool m_debug_gl_call;
 	static FILE* m_debug_gl_file;

plugins/GSdx/GSRendererDX.cpp

@@ -478,7 +478,7 @@ void GSRendererDX::DrawPrims(GSTexture* rt, GSTexture* ds, GSTextureCache::Sourc
 		// After the conversion the texture will be RGBA8 (aka 32 bits) hence the 0 below
 		int gpu_tex_fmt = (tex->m_target) ? cpsm.fmt : 0;
 
-		bool bilinear = m_filter == 2 ? m_vt.IsLinear() : m_filter != 0;
+		bool bilinear = m_filter == 2 || m_filter == 4 ? m_vt.IsLinear() : m_filter != 0;
 		bool simple_sample = !tex->m_palette && gpu_tex_fmt == 0 && m_context->CLAMP.WMS < 2 && m_context->CLAMP.WMT < 2;
 		// Don't force extra filtering on sprite (it creates various upscaling issue)
 		bilinear &= !((m_vt.m_primclass == GS_SPRITE_CLASS) && m_userhacks_round_sprite_offset && !m_vt.IsLinear());

plugins/GSdx/GSRendererHW.cpp

@@ -571,7 +571,7 @@ void GSRendererHW::Draw()
 		tex = tex_psm.depth ? m_tc->LookupDepthSource(TEX0, env.TEXA, r) : m_tc->LookupSource(TEX0, env.TEXA, r);
 
 		// Round 2
-		if (IsMipMapActive() && m_mipmap > 1 && !tex_psm.depth) {
+		if (IsMipMapActive() && m_mipmap == 2 && !tex_psm.depth) {
 			// Upload remaining texture layers
 			GSVector4 tmin = m_vt.m_min.t;
 			GSVector4 tmax = m_vt.m_max.t;

plugins/GSdx/GSRendererOGL.cpp

@@ -747,9 +747,45 @@ void GSRendererOGL::EmulateTextureSampler(const GSTextureCache::Source* tex)
 	const uint8 wmt = m_context->CLAMP.WMT;
 	bool complex_wms_wmt = !!((wms | wmt) & 2);
 
-	bool mipmap = m_mipmap > 1 && m_context->TEX1.MMIN > 1;
+	bool need_mipmap = IsMipMapDraw();
-	bool bilinear = m_filter == 2 ? m_vt.IsLinear() : m_filter != 0;
 	bool shader_emulated_sampler = tex->m_palette || cpsm.fmt != 0 || complex_wms_wmt || psm.depth;
+	bool trilinear_manual = need_mipmap && m_mipmap == 2;
+
+	bool bilinear = false;
+	int trilinear = 0;
+	bool trilinear_auto = false;
+	switch (m_filter) {
+		case 0: // Nearest
+			bilinear = false;
+			break;
+		case 1: // Forced Bilinear
+			bilinear = true;
+			break;
+		case 2: // Bilinear PS2
+			bilinear = m_vt.IsLinear();
+			break;
+		case 3: // Trilinear Forced
+			bilinear = true;
+			trilinear = static_cast<uint8>(GS_MIN_FILTER::Linear_Mipmap_Linear);
+			trilinear_auto = m_mipmap != 2;
+			break;
+		case 4: // Trilinear
+			bilinear = m_vt.IsLinear();
+			if (need_mipmap && m_mipmap != 2) {
+				trilinear = m_context->TEX1.MMIN;
+				trilinear_auto = true;
+			}
+			break;
+		case 5: // Trilinear (forced on linear)
+			bilinear = true;
+			if (need_mipmap && m_mipmap != 2) {
+				trilinear = (m_context->TEX1.MMIN | 4) & 0x5;
+				trilinear_auto = true;
+			}
+		default:
+			break;
+	}
+
 	// Don't force extra filtering on sprite (it creates various upscaling issue)
 	bilinear &= !((m_vt.m_primclass == GS_SPRITE_CLASS) && m_userhacks_round_sprite_offset && !m_vt.IsLinear());
 
@@ -875,12 +911,14 @@ void GSRendererOGL::EmulateTextureSampler(const GSTextureCache::Source* tex)
 	if (complex_wms_wmt) {
 		ps_cb.MskFix = GSVector4i(m_context->CLAMP.MINU, m_context->CLAMP.MINV, m_context->CLAMP.MAXU, m_context->CLAMP.MAXV);
 		ps_cb.MinMax = GSVector4(ps_cb.MskFix) / WH.xyxy();
-	} else if (mipmap) {
+	} else if (trilinear_manual) {
 		// Reuse MinMax for mipmap parameter to avoid an extension of the UBO
 		ps_cb.MinMax.x = (float)m_context->TEX1.K / 16.0f;
 		ps_cb.MinMax.y = float(1 << m_context->TEX1.L);
 		ps_cb.MinMax.z = float(m_lod.x); // Offset because first layer is m_lod, dunno if we can do better
 		ps_cb.MinMax.w = float(m_lod.y);
+	} else if (trilinear_auto) {
+		tex->m_texture->GenerateMipmap();
 	}
 
 	// TC Offset Hack
@@ -898,11 +936,11 @@ void GSRendererOGL::EmulateTextureSampler(const GSTextureCache::Source* tex)
 	} else {
 		m_ps_ssel.biln  = bilinear;
 		m_ps_ssel.aniso = 1;
-		if (mipmap) {
+		m_ps_ssel.triln = trilinear;
-			m_ps_ssel.triln = m_context->TEX1.MMIN;
+		if (trilinear_manual) {
 			m_ps_sel.manual_lod = 1;
-		} else {
+		} else if (trilinear_auto) {
-			m_ps_ssel.triln = m_context->TEX1.MMIN & 1;
+			m_ps_sel.automatic_lod = 1;
 		}
 	}